CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
88.6%
The version of squid installed on the remote host is prior to 4.15-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2SQUID4-2023-010 advisory.
An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request.
If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker’s HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI. (CVE-2019-12520)
An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALASSQUID4-2023-010.
##
include('compat.inc');
if (description)
{
script_id(182658);
script_version("1.1");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/17");
script_cve_id("CVE-2019-12520", "CVE-2019-12524", "CVE-2022-41317");
script_name(english:"Amazon Linux 2 : squid (ALASSQUID4-2023-010)");
script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
script_set_attribute(attribute:"description", value:
"The version of squid installed on the remote host is prior to 4.15-1. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2SQUID4-2023-010 advisory.
- An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to
see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request.
If found, it servers the request. The absolute URL can include the decoded UserInfo (username and
password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to
provide a username that has special characters to delimit the domain, and treat the rest of the URL as a
path or query string. An attacker could first make a request to their domain using an encoded username,
then when a request for the target domain comes in that decodes to the exact URL, it will serve the
attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows
an attacker to gain access to features that only reverse proxies can use, such as ESI. (CVE-2019-12520)
- An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to
see if the request should be denied. Squid by default comes with rules to block access to the Cache
Manager, which serves detailed server information meant for the maintainer. This rule is implemented via
url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to
encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/AL2/ALASSQUID4-2023-010.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-12520.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-12524.html");
script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2022-41317.html");
script_set_attribute(attribute:"solution", value:
"Run 'yum update squid' to update your system.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-12524");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/15");
script_set_attribute(attribute:"patch_publication_date", value:"2023/09/27");
script_set_attribute(attribute:"plugin_publication_date", value:"2023/10/06");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:squid");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:squid-debuginfo");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Amazon Linux Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
var pkgs = [
{'reference':'squid-4.15-1.amzn2.0.5', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-4.15-1.amzn2.0.5', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-4.15-1.amzn2.0.5', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-debuginfo-4.15-1.amzn2.0.5', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-debuginfo-4.15-1.amzn2.0.5', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
{'reference':'squid-debuginfo-4.15-1.amzn2.0.5', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'}
];
var flag = 0;
foreach var package_array ( pkgs ) {
var reference = NULL;
var _release = NULL;
var sp = NULL;
var _cpu = NULL;
var el_string = NULL;
var rpm_spec_vers_cmp = NULL;
var epoch = NULL;
var allowmaj = NULL;
var exists_check = NULL;
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (!empty_or_null(package_array['release'])) _release = package_array['release'];
if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
extra : rpm_report_get()
);
exit(0);
}
else
{
var tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "squid / squid-debuginfo");
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12520
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12524
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-41317
alas.aws.amazon.com/AL2/ALASSQUID4-2023-010.html
alas.aws.amazon.com/cve/html/CVE-2019-12520.html
alas.aws.amazon.com/cve/html/CVE-2019-12524.html
alas.aws.amazon.com/cve/html/CVE-2022-41317.html
alas.aws.amazon.com/faqs.html
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
88.6%